Template:If then wikilink/doc

If the first unnamed parameter is not an empty string, the template returns it as a piped wiki-link using the prefix as a namespace or interwiki prefix. Otherwise it returns the second unnamed parameter.

This is only useful when the first parameter is a of a Lua module that may return a value or nothing. Because it uses the just once, it simplifies the coding of infoboxes and reduces the calls to a module.

The after parameter is emitted immediately after the wikilink. This is useful, e.g., for tracking categories.

The linktext parameter allows the link text of the wikilink to be overridden. Otherwise, it will be the same as the first positional argument.